Pharmaceutical drugs now pollute Lake Michigan, study confirms

Following the release of several reports in recent years highlighting the presence of pharmaceutical contaminants in many of the nation’s drinking water supplies, a new study published in the Elsevier journal Chemosphere reveals that pharmaceuticals are now turning up in large quantities in the Great Lakes as well. A summary of this new research recently put out byEnvironmental Health News reveals disturbing levels of undiluted pharmaceuticals just two miles from Milwaukee’s main wastewater outfalls.

For their study, researchers from the University of Wisconsin – Milwaukee’s School of Freshwater Sciences and the University of Wisconsin – Madison’s State Laboratory of Hygiene conducted tests on water samples collected from various spots in Lake Michigan, both close to shore and out to deeper waters. The team looked specifically for the presence of 54 pharmaceuticals and personal care products (PPCPs) in these samples, which came from both surface water and sediment that was sampled over the course of two years.

Upon analysis, it was determined that 32 different PPCPs were present in Lake Michigan water, and 30 in Lake Michigan sediment. Several of these PPCPs were also identified up to 3.2 kilometers, or about two miles, away from the city. Among these were metformin, a popular oral anti-diabetic drug; caffeine; the antibiotic sulfamethoxazole; and triclosan, a toxic antibacterial and antibiotic compound found in many conventional hand soap and toothpaste brands.

According to the study’s abstract, the team determined the ecological risk of these substances by measuring their maximum environmental concentrations as detected in the lake and comparing them to the predicted “no-effect” concentrations. From this, they determined that 14 PPCPs present in the lake are currently of “medium or high ecological risk,” meaning they are a threat to both animal life and humans. And the greatest concentrations of these chemicals were found near the shore, where people wade at beaches and algae and other aquatic life abounds.

“In a body of water[2] like the Great Lakes, you’d expect dilution would kick in and decrease concentrations,” says Dana Kolpin, a U.S. Geological Survey (USGS) research hydrologist based out of Iowa, as quoted by Environmental Health News. “That was not the case here,” she adds, noting that these new discoveries contradict previously held assumptions.

Worst consequences of pharmaceutical runoff could take years to rear their ugly head, say experts

While the immediate effects of this widespread pollution problem are still largely unknown, we do know that many of these drug compounds have already been shown to change the behaviors and hormone profiles of various animals, as evidenced by previous studies. This implies that humans may also be at risk, especially as the sheer volume of pharmaceutical runoff increases over time.

“You’re not going to see fish die-offs [from pharmaceuticals] but subtle changes in how the fish eat and socialize that can have a big impact down the road,” adds Kolpin. “With behavior changes and endocrine disruption, reproduction and survival problems may not rear their ugly head for generations.”

Since federal regulations for PPCPs in water are currently non-existent, the problem will most likely persist until proactive solutions are eventually implemented. It is also important to note that most PPCPs are not filtered out by wastewater treatment plants, as the filtration systems currently used by most of them were not designed to capture these pervasive compounds. This means that these toxins end up being dumped right back into waterways unchanged.

“People should reconsider the notion that the Great Lakes are so large that this stuff cannot hurt us,” adds Olga Lyandres, a research manager with the Alliance for the Great Lakes organization. “The stuff you excrete and wash down the drain ends up in the same bodies of water that you drink out of.”